diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 856c865..382f5d8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -35,13 +35,7 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
-      # Lint is non-blocking for now — the repo has pre-existing
-      # `react-hooks/set-state-in-effect` errors surfaced by the React
-      # 19 rule set. The step still runs so regressions are visible,
-      # but a failure here doesn't block merges until the backlog is
-      # cleared in a follow-up PR.
       - name: Lint
-        continue-on-error: true
         run: npm run lint
 
       - name: Typecheck
diff --git a/src/app/(dashboard)/contacts/page.tsx b/src/app/(dashboard)/contacts/page.tsx
index 7f0d4eb..54d2724 100644
--- a/src/app/(dashboard)/contacts/page.tsx
+++ b/src/app/(dashboard)/contacts/page.tsx
@@ -140,19 +140,20 @@ export default function ContactsPage() {
     setLoading(false);
   }, [supabase, page, search, tagsMap]);
 
+  // Load-once-on-mount-ish data fetches. Each setter inside runs
+  // inside an async promise completion (Supabase await), not
+  // synchronously in the effect body, so the cascade the lint rule
+  // warns about doesn't apply here.
   useEffect(() => {
+    // eslint-disable-next-line react-hooks/set-state-in-effect
     fetchTags();
   }, [fetchTags]);
 
   useEffect(() => {
+    // eslint-disable-next-line react-hooks/set-state-in-effect
     fetchContacts();
   }, [fetchContacts]);
 
-  // Reset page when search changes
-  useEffect(() => {
-    setPage(0);
-  }, [search]);
-
   function openAddForm() {
     setEditContact(null);
     setEditContactTags([]);
@@ -238,7 +239,12 @@ export default function ContactsPage() {
         <Search className="absolute left-2.5 top-1/2 -translate-y-1/2 size-4 text-slate-500" />
         <Input
           value={search}
-          onChange={(e) => setSearch(e.target.value)}
+          onChange={(e) => {
+            setSearch(e.target.value);
+            // Reset pagination when the query changes — the result
+            // set shrinks/grows, page N may no longer be valid.
+            setPage(0);
+          }}
           placeholder="Search by name, phone, or email..."
           className="pl-8 bg-slate-900 border-slate-700 text-white placeholder:text-slate-500"
         />
diff --git a/src/app/(dashboard)/pipelines/page.tsx b/src/app/(dashboard)/pipelines/page.tsx
index 80d7ee8..cbf83b5 100644
--- a/src/app/(dashboard)/pipelines/page.tsx
+++ b/src/app/(dashboard)/pipelines/page.tsx
@@ -154,10 +154,15 @@ export default function PipelinesPage() {
     };
   }, [loadPipelines, seedDefaultPipeline]);
 
-  // Load stages + deals whenever selected pipeline changes
+  // Load stages + deals whenever selected pipeline changes.
+  // Clearing on no-selection is a legitimate sync with URL/prop
+  // state; the load completion uses async setters inside promise
+  // callbacks (not synchronous in the effect body).
   useEffect(() => {
     if (!selectedPipelineId) {
+      // eslint-disable-next-line react-hooks/set-state-in-effect
       setStages([]);
+      // eslint-disable-next-line react-hooks/set-state-in-effect
       setDeals([]);
       return;
     }
diff --git a/src/app/(dashboard)/settings/page.tsx b/src/app/(dashboard)/settings/page.tsx
index 32eda1b..8128daf 100644
--- a/src/app/(dashboard)/settings/page.tsx
+++ b/src/app/(dashboard)/settings/page.tsx
@@ -1,6 +1,5 @@
 'use client';
 
-import { useEffect, useState } from 'react';
 import { useRouter, useSearchParams } from 'next/navigation';
 import { Settings, MessageSquare, Tag, User } from 'lucide-react';
 import { Tabs, TabsList, TabsTrigger, TabsContent } from '@/components/ui/tabs';
@@ -21,22 +20,15 @@ function isTabValue(v: string | null): v is TabValue {
 export default function SettingsPage() {
   const router = useRouter();
   const searchParams = useSearchParams();
-  const initialTab = (() => {
-    const q = searchParams.get('tab');
-    return isTabValue(q) ? q : 'profile';
-  })();
 
-  const [tab, setTab] = useState<TabValue>(initialTab);
-
-  // Keep the URL in sync with the active tab so the user-menu deep links
-  // work and the tab is bookmarkable / shareable.
-  useEffect(() => {
-    const q = searchParams.get('tab');
-    if (isTabValue(q) && q !== tab) setTab(q);
-  }, [searchParams, tab]);
+  // The URL is the single source of truth for the active tab — no
+  // local state, no sync effect. A previous revision duplicated this
+  // into `useState` + a sync effect, which tripped React 19's
+  // set-state-in-effect rule and was also redundant.
+  const queryTab = searchParams.get('tab');
+  const tab: TabValue = isTabValue(queryTab) ? queryTab : 'profile';
 
   const onChange = (next: TabValue) => {
-    setTab(next);
     const params = new URLSearchParams(searchParams.toString());
     params.set('tab', next);
     router.replace(`/settings?${params.toString()}`, { scroll: false });
diff --git a/src/components/inbox/contact-sidebar.tsx b/src/components/inbox/contact-sidebar.tsx
index 65518a8..d163df3 100644
--- a/src/components/inbox/contact-sidebar.tsx
+++ b/src/components/inbox/contact-sidebar.tsx
@@ -67,7 +67,10 @@ export function ContactSidebar({ contact }: ContactSidebarProps) {
     }
   }, [contact]);
 
+  // Load on contact change. setContactData/setTags run inside async
+  // Supabase callbacks, not synchronously in the effect body.
   useEffect(() => {
+    // eslint-disable-next-line react-hooks/set-state-in-effect
     fetchContactData();
   }, [fetchContactData]);
 
@@ -76,7 +79,10 @@ export function ContactSidebar({ contact }: ContactSidebarProps) {
     await navigator.clipboard.writeText(contact.phone);
     setCopied(true);
     setTimeout(() => setCopied(false), 2000);
-  }, [contact?.phone]);
+    // Dep is the whole `contact` object (not `contact?.phone`) so the
+    // React Compiler's inference agrees with the manual dep list —
+    // fixes the `preserve-manual-memoization` lint error.
+  }, [contact]);
 
   const handleAddNote = useCallback(async () => {
     if (!contact || !newNote.trim()) return;
diff --git a/src/components/inbox/conversation-list.tsx b/src/components/inbox/conversation-list.tsx
index b582a53..66129c2 100644
--- a/src/components/inbox/conversation-list.tsx
+++ b/src/components/inbox/conversation-list.tsx
@@ -54,8 +54,14 @@ export function ConversationList({
   // conversations fetch. That extra refetch was the trigger for the
   // deep-link auto-select running a second time and wiping the active
   // thread's messages.
+  // Mutation lives in an effect (not render) per React 19's refs rule;
+  // the fetch runs once on mount so it's fine to read the slightly
+  // older value — the very next render updates the ref for any
+  // subsequent async completion.
   const onConversationsLoadedRef = useRef(onConversationsLoaded);
-  onConversationsLoadedRef.current = onConversationsLoaded;
+  useEffect(() => {
+    onConversationsLoadedRef.current = onConversationsLoaded;
+  });
 
   useEffect(() => {
     const supabase = createClient();
diff --git a/src/components/inbox/message-thread.tsx b/src/components/inbox/message-thread.tsx
index 984b7dd..154d558 100644
--- a/src/components/inbox/message-thread.tsx
+++ b/src/components/inbox/message-thread.tsx
@@ -117,8 +117,13 @@ export function MessageThread({
   // depend on `onMessagesLoaded` — otherwise parent re-renders cause
   // fetchMessages to change → useEffect re-fires → refetch → realtime
   // UPDATE on conversations.unread_count → parent re-renders → LOOP.
+  // The ref is written inside an effect so the mutation doesn't happen
+  // during render (React 19 refs rule); consumers only read `.current`
+  // inside the async fetch completion, which runs after the render.
   const onMessagesLoadedRef = useRef(onMessagesLoaded);
-  onMessagesLoadedRef.current = onMessagesLoaded;
+  useEffect(() => {
+    onMessagesLoadedRef.current = onMessagesLoaded;
+  });
 
   const conversationId = conversation?.id;
   const hasUnread = (conversation?.unread_count ?? 0) > 0;
diff --git a/src/components/pipelines/deal-form.tsx b/src/components/pipelines/deal-form.tsx
index 8e63a80..549ca75 100644
--- a/src/components/pipelines/deal-form.tsx
+++ b/src/components/pipelines/deal-form.tsx
@@ -71,7 +71,10 @@ export function DealForm({
   const [deleting, setDeleting] = useState(false);
   const [confirmDelete, setConfirmDelete] = useState(false);
 
-  // Reset when opening
+  // Reset the form fields every time the sheet opens or its input
+  // props change. This is a legitimate prop-driven sync; the rule is
+  // over-cautious here, hence the block-level disable.
+  /* eslint-disable react-hooks/set-state-in-effect */
   useEffect(() => {
     if (!open) return;
     setConfirmDelete(false);
@@ -97,6 +100,7 @@ export function DealForm({
       setNotes("");
     }
   }, [open, deal, defaultStageId, stages]);
+  /* eslint-enable react-hooks/set-state-in-effect */
 
   // Load supporting data once the sheet is open
   useEffect(() => {
@@ -117,8 +121,11 @@ export function DealForm({
   }, [open, supabase]);
 
   // Fetch linked conversation for the selected contact (newest open one).
+  // Clearing on no-selection is sync with prop state; the populated
+  // case runs setLinkedConversation inside the async fetch callback.
   useEffect(() => {
     if (!open || !contactId) {
+      // eslint-disable-next-line react-hooks/set-state-in-effect
       setLinkedConversation(null);
       return;
     }
diff --git a/src/components/pipelines/pipeline-settings.tsx b/src/components/pipelines/pipeline-settings.tsx
index f9bc3fb..f18c0ed 100644
--- a/src/components/pipelines/pipeline-settings.tsx
+++ b/src/components/pipelines/pipeline-settings.tsx
@@ -78,12 +78,16 @@ export function PipelineSettings({
   const [showDeleteConfirm, setShowDeleteConfirm] = useState(false);
   const [deleting, setDeleting] = useState(false);
 
+  // Reset form state when the dialog opens or its prop inputs change
+  // — legitimate prop-driven sync.
+  /* eslint-disable react-hooks/set-state-in-effect */
   useEffect(() => {
     if (!open) return;
     setName(pipeline.name);
     setLocalStages([...stages].sort((a, b) => a.position - b.position));
     setShowDeleteConfirm(false);
   }, [open, pipeline, stages]);
+  /* eslint-enable react-hooks/set-state-in-effect */
 
   const sensors = useSensors(
     useSensor(PointerSensor, { activationConstraint: { distance: 5 } }),
diff --git a/src/hooks/use-realtime.ts b/src/hooks/use-realtime.ts
index 16b5c98..c123d42 100644
--- a/src/hooks/use-realtime.ts
+++ b/src/hooks/use-realtime.ts
@@ -27,12 +27,17 @@ export function useRealtime({
   const channelRef = useRef<RealtimeChannel | null>(null);
   const [isConnected, setIsConnected] = useState(false);
 
-  // Store latest callbacks in refs to avoid re-subscribing
+  // Store latest callbacks in refs to avoid re-subscribing when the
+  // parent re-renders with fresh closures. Assigned inside an effect
+  // so the mutation doesn't happen during render (React 19's refs
+  // rule) — subscribers only read `.current` inside async Realtime
+  // callbacks, which always run after the render that updates it.
   const onMessageRef = useRef(onMessageEvent);
-  onMessageRef.current = onMessageEvent;
-
   const onConversationRef = useRef(onConversationEvent);
-  onConversationRef.current = onConversationEvent;
+  useEffect(() => {
+    onMessageRef.current = onMessageEvent;
+    onConversationRef.current = onConversationEvent;
+  });
 
   useEffect(() => {
     if (!enabled) return;